package com.jiandp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.jiandp.dto.Result;
import com.jiandp.entity.VoucherOrder;
import com.jiandp.mapper.VoucherOrderMapper;
import com.jiandp.service.ISeckillVoucherService;
import com.jiandp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.jiandp.utils.RedisIdWorker;
import com.jiandp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {
    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT=   new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }
    private class VoucherOrderHandler implements Runnable{
        String queueName = "stream.orders";
        @Override
        public void run() {
            while (true){
                //1.获取队列中的订单信息
                try {
                    //1.获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );

                    //2.判断消息是否获取成功
                    if (list==null||list.isEmpty()) {
                        //2.1如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);

                    //3.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                    //创建订单

                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    handlePendingList();
                }
            }

        }
        private void handlePendingList() {
            while (true){
                //1.获取队列中的订单信息
                try {
                    //1.获取消息队列中的订单信息
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );

                    //2.判断消息是否获取成功
                    if (list==null||list.isEmpty()) {
                        //2.1如果获取失败，说明没有消息，结束循环
                        break;
                    }
                    //解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);

                    //3.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //4.ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());

                    //创建订单

                } catch (Exception e) {
                    log.error("处理订单异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException interruptedException) {
                        interruptedException.printStackTrace();
                    }

                }
            }
        }
    }


 /*   private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    private class VoucherOrderHandler implements Runnable{
        @Override
        public void run() {
            while (true){
                //1.获取队列中的订单信息
                try {
                    //获取队列中的订单信息
                    VoucherOrder voucherOrder =orderTasks.take();
                    //创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (InterruptedException e) {
                    log.error("处理订单异常",e);
                }
            }

        }
    }*/

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        //创建锁的对象
        Long userId = voucherOrder.getUserId();
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        if (!isLock){
            log.error("不允许重复下单");
            return ;

        }
        try {
            //获取代理对象（事务）

           proxy.createVoucherOrder(voucherOrder);
        } finally {
            lock.unlock();
        }
    }
    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");

        //执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(),String.valueOf(orderId)
        );
        //判断结果是否为0
        int r = result.intValue();
        if (r!=0){
            //不为0没有购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }

        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();

        //7.返回订单id
        return Result.ok(orderId);

    }



/*

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户id
        Long userId = UserHolder.getUser().getId();

        //执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString()
        );
        //判断结果是否为0
        int r = result.intValue();
        if (r!=0){
            //不为0没有购买资格
            return Result.fail(r==1?"库存不足":"不能重复下单");
        }
        //为0有购买资格，把下单信息保存到阻塞队列
        //创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        //6.1订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        //6.2用户id
        voucherOrder.setUserId(userId);
        //6.3代金券id
        voucherOrder.setVoucherId(voucherId);
        //放入阻塞队列
        orderTasks.add(voucherOrder);

        //获取代理对象
        proxy=(IVoucherOrderService) AopContext.currentProxy();

        //7.返回订单id
        return Result.ok(orderId);

    }
*/

 /*   @Override
    public Result seckillVoucher(Long voucherId) {
        //查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);

        //判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())){
            return Result.fail("秒杀尚未开始");
        }
        //判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())){
            return Result.fail("秒杀已经结束");
        }

        //判断库存是否充足
        if (voucher.getStock()<1) {
            //库存不足
            return Result.fail("库存不足!");
        }
        Long userId = UserHolder.getUser().getId();
        //创建锁的对象
       // SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
        if (!isLock){
            return Result.fail("一个用户只允许下一单");

        }
        try {
            //获取代理对象（事务）
            IVoucherOrderService proxy=(IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        } finally {
            lock.unlock();
        }

    }*/
    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();
            //查询订单
            Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
            //判断是否存在
            if (count > 0) {
             log.error("用户已经购买过一次了");
                return ;
            }
            //


            //扣减库存
            Boolean success = seckillVoucherService.update()
                    .setSql("stock = stock - 1")
                    .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();
            if (!success) {
                //扣减失败
                log.error("库存不足");
                return ;
            }


            save(voucherOrder);

        }

}
